Additive well pump



April 19, 1960 E. SCRIVNER ADDITIVE WELL PUMP led June 10, 1951 Wwww.ED/THZ Joe/mfg United States Patent C) ADDITIVE WELL PUMP Edith I.Scrivner, Lakewood, Calif.

Application June 10, 1957, Serial No. 664,567

3 Claims. (Cl. 103-1) This invention relates to well pumping equipmentand more particularly to pumps used in producing oil wells.

In the use of well pumping equipment for the production of viscous crudeoils, for example, the usual practice is to install means such as areciprocating type of pump at a point below the fluid level in the welland operate the pump by an elongated member or sucker rod extendingthroughout the production tubing leading upwardly from the pump to thesurface of the ground. At the upper end of the sucker rod a motor orengine is provided to impart a reciprocating motion to the sucker rod.The means for translating the motor rotation to the reciprocating rod ismost generally a walking beam supported upon a suitable fulcrum anddriven by a crank from the slow speedmotor.

In such an arrangement where the heavy oil surrounds the sucker rodthroughout its length, the rate of travel of the rod is limitedsince itsdescent due to gravity is retarded by the effect of the heavy fluid.Accordingly, the capacity of the pump is reduced.

In addition, crude oil and other fluids pumped from the earth containforeign matter and chemicals which have a deleterious effect on theproduction tubing and sucker rod. For example, encrustations anddeposits are formed on the rod and the interior of the tubing whichreduce the area through which the oil may flow upward.

For these and other reasons it is desirable in many pumping operationsto introduce chemical additives to the crude oil or other fluid toincrease the efiiciency of the pumping apparatus. That is, if heavy orviscous oil is being pumped it is advantageous to introduce a lowviscosity fluid as a diluent which produces a condition which is morefavorable to the eflicient pumping of viscuous oil from wells. In otherinstances it is desirable to introduce a chemical additive whichprevents the accumulation of encrustations or deposits in the fluidpassage from the well and around the sucker rod.

Accordingly, it is an object of the present invention to provide animproved well pump by which additive fluid may be introduced into thefluid being pumped in predetermined amounts.

It is another object of the present invention to provide an improvedreciprocating well pump in which additive fluids are introduced onlyinto the fluid which has entered the pumping apparatus.

It is a further object of the present invention to provide an improvedwell pumping apparatus in which the composition of the fluid flowingthrough the apparatus is accurately controlled.

It is another object of the present invention to provide an improvedmixing pump for wells in which the additive fluid and the mixed wellfluid are contained within the pumping apparatus.

The present invention is an improved well pump for mixing an additivefluid to the fluid being pumped and comprises a lower working barrelhaving an .additive fluid inlet thereto and an upper working barrelpositioned above the lower barrel and. separated therefrom by a2,933,042 Patented Apr. 19, 1960 mixing chamber. A first hollow plungeris reciprocable in the lower working barrel, and a second hollow plungeris reciprocable in the upper working barrel with the plungers beingoperably connected in a sucker rod string. A standing valve at the lowerend of the lower working barrel allows entrance of additive fluid to thelower barrel which is pumped through the lower barrel to the mixingchamber by means of appropriate traveling valving. A second standingvalve allows entrance of fluid from the well bore to the mixing chamberat the lower end of the upper working barrel. Traveling valve means onthe upper plunger permit the mixed fluid to be pumped from the mixingchamber to the tubing string. The upper and lower plungers are ofpredetermined diameters depend ent upon the ratio of additive fluid tobe mixed with the well fluid.

The novel features which are believed to be characteristic of theinvention, both as to its organization and method of operation, togetherwith further objects and advantages thereof, will be better understoodfrom the following description considered in connection with theaccompanying drawing in which a presently preferred embodiment isillustrated by way of example. It is to be expressly understood,however, that the drawing is for the purpose of illustration anddescription only, and is not intended as a definition of the limits ofthe invention.

Figure 1 is a partially sectional view in elevation of the presentlypreferred embodiment of this invention disposed within a well casing;

Figure 2 is a view in cross-section of the pump of the presentinvention;

Figure 3 is a view taken along line 3-3 of Figure 2; and

Figure 4 is a view taken along line 44 of Figure 2.

Referring now to the drawing, the well casing 11 is supported at itsupper end by a pumping head of any preferred form. Branch pipesextending from the casing serve to convey any gas that the well may beproducing while the oil or fluid being pumped flows upward through theproduction tubing 12 and is discharged through a discharge pipe. Apolish rod passes through a stufling box at the top of the pumping headand is connected to the sucker rod 14. The pumping and dischargearrangement and apparatus are not shown or described in detail sincethey may be of any type known to the prior art and form no part of thepresent invention.

As shown in Figs. 1 and 2, the mixing pump of the present inventioncomprises an upper pump section 15 and a lower pump section 16 which areinterconnected and adapted to be lowered into the well casing 11containing a fluid, such as oil, which is to be pumped to the surface.The upper pump section 15 comprises a barrel 17 which is connected atits upper end which is the outlet end of the pump section to the loweropen end 27 of the production tubing 12 through which the oil is pumpedto the surface. The drawing is partially schematic and various unionsand connections and standard pump parts of a type well known to the artmay be used throughout the present invention. In the illustrativeembodiment, the upper pump barrel 17 is connected to the inlet end 27 ofthe tubing -12 by means of a connecting collar 19 which is femalethreaded and mateable with the male threads of the tubing 12, and malethreaded at its lower end to be mateable with female threads at theupper end of the barrel. Thus, the barrel 17 is removably connected tothe tubing. An upper pump plunger 20 is tubular in configuration and hasan outside diameter substantially equal to but less than the insidediameter of the barrel 17 with a longitudinal opening 18 therethrough.The upper end of the plunger 20 is aflixed to the sucker rod 14 througha traveling valve '21 of the type well'known to the art which allows thepassage of fluid upward through the plunger 20 and valve 21, butprevents the flow of [fluid downward and into the plunger. In theembodiment shown the traveling valve 21 comprises a seat 22 having anopening 23 therethrough which is threadably mateable with the plunger20. The valve cage 24 is in turn threaded upon the seat and encloses aball check 25 which is mateable with the seat 22 to close the opening 23when fluid attempts to flow downward therethrough. The ball 25 is freewithin the cage 24 and openings 26 are provided in the cage to allowpassage of fluid when the upward flow of fluid lifts the ball 25 fromits seat 22. The cage 24 is threadably connected to the lower end of thesucker rod 14, thus affixing the upper plunger 20 to the sucker rod forvertical reciprocating movement therewith within the upper barrel. As iswell known in the art the volume of fluid pumped by the upper plunger issubstantially equal to the internal cross-sectional area of the barreltimes the length of stroke as will be further described in connectionwith the operation of the apparatus in its presently preferred form.

At the lower end 62 of the upper barrel 17, which forms the fluid inletof the upper pump section 15, a mixing chamber 29 is defined by theinterior of a vertically disposed housing formed by a tubular section 30of predetermined length. The chamber tubing 30 is threadably connectedto the lower end of the upper barrel 17 and is decreased in diameter atits lower end. At the lower end of the chamber tubing 30 a lower pumpbarrel 33 is connected at the upper end 35 thereof by a connectingcollar 34 which is mateable with male threads on the chamber tubing 30and female threads on the lower barrel 33, as previously described. Aprotrusion 36 is provided at one side of the chamber tubing 30 to definea slip joint 37, of the type known to the art, into which a fluidconduit 38 may be slidably engaged. That is, the protrusion defines acylinder having an inside diameter substantially equal to the outsidediameter of the fluid conduit and forming a fluid inlet 43 through astanding valve 40 into the mixing chamber 29. The standing valve is ofthe type well known to the art having a ball check 41 contained Within acage 42 and mateable with the fluid inlet 43 to allow the passage offluid from the conduit 38 into the mixing chamber but to prevent flow offluid outward from the chamber.

As described hereinbefore the lower barrel 33 is affixed at the lowerend of the chamber tubing 30 such that the upper end 35, which is theoutlet end of the lower pump section 16, is in fluid communication withthe mixing chamber 19. The lower barrel 33 is of substantially lesserinside diameter than the upper barrel 17. A lower pump plunger 45 of thetype well known to the art is provided for reciprocating movement withinthe lower barrel and is again tubular in configuration with an outsidediameter substantially equal to the inside diameter of the barrel 33.The upper plunger 20 and the lower plunger 45 are interconnected by aconnecting rod 46 which is connected to the upper plunger 20 at thelower end thereof through a spider 47 or similar connecting means whichallows the passage of fluid into the opening 18 of the plunger. Theconnecting rod is connected to the lower pump plunger 45 at the upperend thereof through a traveling valve of the type well known to the artand similar to that described at the upper end of the upper plunger.That is, a ball check 48 is contained within a cage 49 which isthreadably connected to the connecting rod 46. The ball 48 is above theseat 50 which is affixed to the plunger 45 and is mateable therewith toallow the upward passage of fluid through the lower plunger 45 but toprevent downward travel of fluid from the mixing chamber 29 into theplunger opening 51.

Thus, the pump plungers 20 and 45 are connected to form a continuousplunger structure and are separated by a mixing chamber from which fluidcan flow only upward through the upper plunger. As discussedhereinbefore, the plungers and respective barrels are of differentdiameters and will pump proportionally different volumes of fluid asdescribed in further detail following.

A length of tubing or sleeve 53 is connected at the lower, or inlet, end61 of the lower barrel to form an extension thereof and has an additivefluid inlet 54 therein to which an additive fluid conduit 55 isconnected by standard fittings or joints. Thus, as shown in Figs. 1through 4, the additive fluid conduit is connected beneath the lowerbarrel and extends upward alongside the pump and tubing 12 within thecasing to the surface where a source S (shown diagrammatically inFigure 1) of fluid to be added to the oil or well fluid is supplied. Aslip joint of the conventional type may be inserted into the fluidconduit for ease of assembly or removal. An hydraulic pump P may be usedat the surface in some applications to furnish suflicieut pressure tothe additive fluid for circulation although gravity pressure will besuflicient for most purposes. Interposed between the additive 'fluidinlet 54 and the lower barrel 33 is a standing valve 56 of theconventional type described hereinbefore to allow the passage ofadditive fluid upward into the lower barrel and plunger but to preventflow of fluid from the lower barrel. A closure 57, such as a pipe blank,is positioned in the sleeve 53 beneath the additive fluid inlet toprevent flow of fluid downward from the inlet 54.

A length of perforated pipe 59 is aflixed beneath the closure 57 havinga connection for the oil conduit 38 to permit oil or other fluid beingpumped to flow from the well through a fluid inlet 43 and the standingvalve 40 and into the mixing chamber. Accordingly, oil from the well isadmitted to the mixing chamber 29 through the standing valve 40 whileadditive fluid is supplied from the surface and is admitted through thesecond standing valve 56 and pumped into the mixing chamber 29 by thelower pump in quantities determined by the diameter of the lower pumpbarrel.

Thus, in operation, referring to the figures the fluid to be added tothe oil being pumped, is supplied from a tank or reservoir (not shown)and flows downward through the conduit 55 to the lower standing valve56. On the downward stroke of the plungers, additive fluid passes upwardthrough the traveling valve 48 of the lower plunger. Simultaneously, oilis admitted through the open pipe 59 and passes through the conduit 38,upward through the standing valve 40 and into the mixing chamber 29. Asthe plungers move upward the traveling valve 48 on the lower plungerseats, and the additive fluid in the barrel 33 above the plunger ismoved into the mixing chamber 29. The volume of additive fluid pumpedinto the chamber is thus equal to the cross-sectional area of the lowerplunger times the length of stroke. The additive fluid and oil admittedto the chamber through the standing valve are mixed in the chamber andthen pumped upward by the upper plunger. Thus, on the downward stroke ofthe plungers the upper plunger traveling valve 21 opens and the mixedfluids within the chamber flow through the traveling valve 21 to the topof the plunger 20. On the upward stroke, the valve 21 seats and a volumeof mixed fluids substantially equal to the cross-sectional area of theupper plunger times the length of stroke is moved upward through theproduction tubing 12. From the foregoing it may be seen that theproportion of additive fluid or diluent to be mixed with the oil beingpumped through the tubing can be predetermined and closely controlled byselection of the correct diameter of the lower plunger and barrel. Thatis, for example, if a three to one ratio of oil to additive fluid isrequired such a ratio is obtained by utilizing a lower plunger andbarrel having a crosssectional area equal to one-third thecross-sectional area of the upper plunger and barrel.

Although the present invention has been described in connection with atraveling plunger type of pump it is equally applicable to a pump of thetraveling barrel type and various modifications in the standard pumpparts and fitting can be made. Thus, the present invention provides animproved additive or mixing pump which allows a predetermined proportionof additive fluid to be mixed in a closed cycle with the oil or otherfluid being pumped through the production tubing, but which does notallow contamination of the fluid in the well itself, nor the loss ofadditive fluid to surrounding areas.

What is claimed is:

1. An improved well pump for mixing an additive' liquid to the wellliquid being pumped through production tubing having a liquid inlet atthe lower open end thereof substantially vertically disposed in a wellcomprising: an upper liquid pump vertically disposed below said tubing,said upper pump having a liquid outlet connected to and communicatingwith the liquid inlet to said production tubing; a tubular sectiondefining a liquid mixing chamber vertically disposed below said upperliquid pump, said tubular section being connected to and in liquidcommunication with the liquid inlet to said upper pump; a lower liquidpump vertically disposed below said tubular section, said lower pumphaving a liquid outlet connected to and in liquid communication withsaid tubular section; an additive liquid inlet to said lower pump,closed conduit means between said liquid inlet to said lower pump and asource of additive liquid at the surface of the well; a well liquidinlet to said mixing chamber; means operatively interconnecting said upper liquid pump and said lower liquid pump such that the pumpingcapacity of said lower pump is substantially less than the pumpingcapacity of said upper pump, whereby said lower pump pumps additiveliquid to said mixing chamber and said upper pump pumps additive liquidand well liquid to said production tubing and from said well.

2. An improved well pump for mixing an additive liquid to the wellliquid being pumped through production tubing having a liquid inlet atthe lower open end thereof substantially vertically disposed in a wellcomprising: an upper pump barrel having a first predetermined insidediameter, a lower pump barrel having a second inside diametersubstantially less than said first diameter and a closed lower end, saidupper and lower pump barrels being vertically disposed and spaced apartby a tubular section defining a mixing chamber, said tubular sectionbeing connected to the lower end of said upper barrel and the upper endof said lower barrel to define a liquid path from the liquid outlet ofsaid lower barrel to the liquid inlet of said upper barrel, said upperbarrel being connected at the upper end thereof to the open end of saidproduction tubing; said tubular section defining a well liquid inlet tosaid mixing chamber; an additive liquid inlet to said lower barrelproximate the closed lower end thereof, closed conduit means from asource of additive liquid at the surface of said well to said additiveliquid inlet; an upper pump plunger for pumping mixed well liquid andadditive liquid reciprocable with respect to said upper barrel, a lowerpump plunger for pumping additive liquid reciprocable with respect tosaid lower barrel, said upper and lower pump plungers having pumpingdiameters proportional to said first and second diameters respectively,said upper and lower plungers being operably interconnected by aconnecting rod connected vertically therebetween, said upper pumpplunger being connected to a sucker rod for reciprocation therewith; andvalving means to allow the flow of additive liquid upward through saidlower barrel to said mixing chamber and to allow the flow of additiveliquid and well liquid through said upper barrel to said productiontubing and from the well.

3. An improved well pump for mixing an additive liquid to the wellliquid being pumped upward through production tubing in a wellcomprising: an upper and lower pump section substantially verticallydisposed in said well, said upper pump section including an uppertubular barrel having a first inside diameter, said upper barrelconnected at the upper end thereof to the lower open end of saidproduction tubing; a vertically disposed tubular section, the interiorsurface of which defines a mixing chamber, said tubular section beingconnected at the upper end thereof to the lower end of said upper barrelin communication therewith; said lower pump section including a lowerbarrel having a second inside diameter substantially less than theinside diameter of said upper barrel, said lower barrel being connectedat the upper end thereof to the lower end of said tubular section andcommunicating with said mixing chamber, said lower barrel having aclosed lower end; a vertically disposed upper traveling plungerreciprocable within said upper barrel; a vertically disposed lowertraveling plunger reciprocable within said lower barrel, said lowerplunger being of substantially lesser diameter than said upper plunger;a connecting rod operatively interconnecting the lower end of said upperplunger and the upper end of said lower plunger; said upper plungerbeing connected at the upper end thereof to a sucker rod forreciprocation therewith; an upper traveling valve on said upper plungerto allow upward travel of liquid from said upper pump section to saidproduction tubing; a lower traveling valve on said lower plunger toallow upward flow of liquid from said lower pump section to said mixingchamber; a first standing valve proximate the closed lower end of saidlower barrel to allow upward flow of liquid to said lower barrel; anadditive liquid inlet to said lower barrel between the closed lower endthereof and said first standing valve; closed conduit means connectedbetween said additive liquid inlet and a source of additive liquid atthe surface of said well; a well liquid inlet to said mixing chamber,and a second standing valve at said well liquid inlet whereby said lowerpump pumps additive liquid to said mixing chamber and said upper pumppumps additive liquid and well liquid to said production tubing and fromsaid well.

References Cited in the file of this patent UNITED STATES PATENTS955,580 Caverno Apr. 19, 1910 966,772 Sattler Aug. 9, 1910 1,104,962Clark July 28, 1914 1,322,236 Fish Nov. 18, 1919 1,421,004 Hibbard June27, 1922 1,597,161 Kellogg et a1. Aug. 24, 1926 1,703,423 Herman Feb.26, 1929 1,703,428 Neilsen Feb. 26, 1929 1,738,136 Bannon Dec. 3, 19291,771,070 Bannon July 22, 1930 2,029,473 Fox Feb. 4, 1936 2,213,807Starbuck Sept. 3, 1940 2,330,781 Langmyhr et al Sept. 28, 1943 2,473,726Payne June 21, 1949 2,567,513 Haines Sept. 11, 1951 2,764,940 Long Oct.2, 1956

